Electronic thermometers are being used ever more widely in the health care industry. Typically these thermometers use a heat-sensitive probe connected to the thermometer circuitry by a cable, and the probe is stored in a sheath or well or other holder associated with the thermometer housing. The probes are used in combination with inexpensive, disposable plastic covers. The probe is quickly inserted in a new probe cover just before a patient's temperature is taken and is easily removed for disposal afterwards. See U.S. Pat. No. 3,929,018. The probes are often easily disconnected from the rest of the thermometer and replaced with another probe in the event of malfunction or contamination of the probe. See U.S. Patent application Ser. No. 473,495, filed May 28, 1974. However, when the user is unaware that the probe is contaminated, he may inadvertently replace the contaminated probe in the well or holder and thereby contaminate the whole thermometer; see U.S. Pat. No. 3,681,991; or the user may even replace the probe in the holder with the used cover still in place on the probe. Subsequent replacement of the probe does not help since each new probe will become contaminated upon insertion into the holder. Only sterilization of the holder, which is part of the thermometer housing, can now alleviate the problem.
Generally when the thermometer is used for oral and rectal temperature measuring it is expedient, psychologically perhaps even more so than hygienically, to use two separate probes as well as two different sets of probe covers. The added expense of a second probe is not inconsequential in the cost of such thermometers.
In use, moisture and debris may attach itself to the probe and eventually fall off and accumulate in the bottom of the well or holder. The accumulation can become a growth medium for infectious matter.